Ice cream with fat-containing coating

ABSTRACT

The invention relates to a method for the production of two-component ice cream, in which a core of ice cream, the surface of which is cooled to at least about -15° C., is dipped into a fat-containing coating solution, in order to form a coating layer, and to the two-component ice cream which can be obtained with the method. Thereby, the fat content of the coating solution should be at least about 10%.

This application is a 371 of PCT/EP97/03995, filed Jul. 23, 1997.

The present invention relates to a method for the production oftwo-component ice cream products, in which a frozen core of ice cream issurrounded by a fat-containing coating. The invention relates further totwo-component ice cream products which can be obtained with a methodaccording to the invention.

BACKGROUND OF THE INVENTION

Two or more component ice cream products, in which a core of ice creamis surrounded by a further layer of ice cream, differing from thecomposition of the core, are generally known in the state of the art andhave been on the market for many years. For the production oftwo-component ice cream, for example having an inner dairy ice core andan outer water ice layer, a water ice solution is filled into a moldcooled to low temperatures, whereby a thin, solid water ice layer formson the inner surface of the mold. After pumping off of the remainder ofthe water ice solution, still in the liquid state, there can beintroduced into the mold—now coated on the inside with a water icelayer—another material, for example dairy ice, whereupon the mold isagain cooled. For removal of the final product, the mold must then beslightly warmed, so that the two-component ice cream can be drawn out ofthe mold without damage. This method yields, however, products in whichthe outer frozen water ice layer has very large ice crystals and is hardand brittle, and when consumed breaks into small parts.

Since this method is also relatively complex and complicated, for theproduction of two-component ice cream products there is increasinglyused the so-called dipping method, with which a core of ice cream,pre-cooled to a certain temperature, is dipped a water ice solution,whereby due to the low temperature of the core a water ice layer formson its surface. The water ice solution can be aerated in advance, whichfavours the formation of small water ice crystals, by which means asandy taste in the final product can be avoided.

EP 0 710 074 teaches for example the production of a combined ice lollythat consists of a core of dairy ice and a water ice coating. The icecream is produced by dipping the core, cooled to below −15° C., in awater ice solution, whereby during the dipping procedure a water icelayer forms on the core. The core covered with the water ice is thanagain cooled, for example by dipping into a cryogenic liquid, in orderto ensure an improved adherence of the water ice layer on the dairy icecore and keep the crystals in the coating solution small.

In Japanese published patent application 61 (86)-56045 there isdisclosed the production of a multi-layer ice cream having greataeration in the coating, in which a core for example of dairy ice orsorbet is dipped into an aqueous sol. The sol is obtained by means ofdissolving 30-50% sugar solids, 3-6% gelatine and 1% albumin and, forstabilizing the air bubbles (aeration) to be provided in the coating, isprovided with 0.3% sugar esters.

U.S. Pat. No. 2,985,263 further describes a method for coating a frozenice product with a aqueous coating solution which for ensuring theadhesion of the aqueous coating solution to the core contains an alkalimetal alginate.

The object of the present invention is thus to make available an icecream with fat-containing coating and a method for the productionthereof, in which the coating is not hard and which does not shatterupon consumption and which has a consistency perceived as soft andcreamy.

The object is achieved by means of a method in which the surface of afrozen core of ice cream is brought to a temperature below at leastabout −15° C., the surface of the core is dipped into a fat-containingice solution for a sufficient length of time, in order for a quantity ofthe solution to form as layer on the core, the coating solution having afat content of at least about 10% and the obtained layer having anaeration between 0 and 30%, referred to the volume of the coatingsolution, and then the whole is again cooled to a surface temperature ofbelow at least about −15° C., in order to harden the fat-containinglayer on the frozen ice core of ice cream.

In a second aspect, the object is achieved by means of a method in whichsurface temperature of a frozen core of ice cream is brought to atemperature below at least about −40° C., the surface of the core isdipped into a fat-containing ice solution for a sufficient period oftime, in order for a quantity of the solution to form as a layer on thecore, whereby the coating solution has a fat content of at least about10% and the obtained layer has an aeration of between 0 to 30%, referredto the volume of the coating solution, whereby the coating layer of theproduct is so obtained has at least storage temperature or lower.

DETAILED DESCRIPTION OF THE INVENTION

The production of the ice core is effected by means of methods known inthe state of art, such as for example extrusion or production in molds.The core may be of conventional ice cream and may contain any proteinscommonly used in the production thereof, such as milk proteins andproteins of vegetable origin. Further, the core may, or may not, beaerated.

Before the dipping procedure, the surface of the core is brought to atemperature of below about −15° C., a temperature in the range fromabout −15° C. to −60° C. being preferred, preferably −30° C. to −60° C.The desired core temperature can be attained by means of dipping fordifferent lengths of time in a cryogenic liquid, for example nitrogen orcarbon dioxide, whereby for example for liquid nitrogen dipping times of7 to 35 seconds, preferably 12 to 18 seconds, have proved to besuitable.

The cooled core is then dipped in the coating solution, which has a fatcontent of least about 10%, preferably 10 to 40% and more preferably hasa fat content in the range from 15% to 25%. A fat content from 15% to18% has proved to be very suitable for the purposes for the invention.

As fat components of the coating solution there can be employed anyknown fat usable in ice cream production, such as animal fats, forexample milk fat, or vegetable fats, such as for example coconut fat,cocoa fat, palm oil, soya oil, palm nut oil or rape oil, or acombination of animal and vegetable fats.

The milk, preferably to be employed for the fat components, can be usedin any known form with different fat contents, whereby in particularliquid milk, cream, concentrated milk, milk powder, thickened skimmedmilk powder, sour cream, yoghurt, curd cheese, buttermilk or kefir haveproved to be suitable.

The proteins in the coating solution may likewise be of animal or alsovegetable origin, whereby with regard to the source of fat likewise inparticular milk suggests itself as a source of protein.

The coating solution can be aerated with air in accordance with knowntechnical methods, whereby an aeration in the coating solution up to 30%is possible, preferably up to 20%. More preferred is an aeration in therange from 0 to 10%, in each case referred to the volume of the coatingsolution, whereby the aeration can be completely omitted, withoutnegatively affecting the organoeleptical characteristics of the finalproduct.

It has now surprisingly been found that by means of the method inaccordance with the invention, even with the indicated low quantities ofaeration in the fat-containing coating, an even, smooth and creamycoating can be obtained.

During the dipping of the ice core therein, the temperature of thecoating solution typically lies in the range from about 0° to about 20°C., whereby with regard to its storage stability a temperature rangefrom 0° to 10° C. is preferred. The temperature of the coating solutionis selected, during the method, in consideration of the temperature ofthe ice core to be dipped, so that during the dipping procedure there iseffected a rapid adherence of the coating solution to the dipped icecore. Thereby, a temperature range from 2° to 4° C. has proved to bevery suitable.

If, in accordance with the second aspect according to the invention, thetemperature of the surface of the ice cream core is brought to below atleast about −40° C., then upon dipping of the frozen ice core into thecoating solution there is brought about, due to the temperature shockowing to the temperature difference between ice core and coatingsolution, a rapid adherence of the coating solution to the core, wherebyin the coating layer only extremely small ice crystals form. With thisaspect, the temperature of the coating solution is thus so selected thata sufficiently great temperature difference between the surfacetemperature and the temperature of the coating solution is madeavailable, the skilled person appropriately selecting the temperature ofthe ice core and that of the coating solution on the basis of theirgeneral knowledge of the art. Preferred temperatures for the surface ofthe ice core lay below about −60° C. The temperature of the coatingsolution can also with this aspect to the invention lie in the aboutindicated range, whereby however due to the storage stability offat-containing solutions and the desired great temperature shock, arange from 2 to 4° C. has proved to be very expedient.

The dipping time of the ice cream core in the coating solution isdetermined primarily by the temperature of the ice core and thetemperature and fat-content of the coating solution. It is, however,typically 0.5 to 20 seconds and is appropriately chosen by the skilledperson on the basis of their general knowledge of the art that theeffects aimed at by the invention are obtained and a layer of thecoating solution can be formed. The dipping processes can be repeated asdesired until the desired layer thickness is attained. Thereby, alsodifferent coating solutions can be employed, whereby ice cream productshaving different coatings in one product to can be obtained.

Furthermore, there can be added to the coating solution furthercomponents known in the state of the art, such as sugar and sugar formsin accordance with the regulations governing sugar forms, stabilizers,such as carob flour, guar, alginate from 0.1 to 0.3% and emulsifiers forexample mono and diglycerides. For flavouring, there may be added asdesired known flavouring materials, but also pieced ingredients, such asfruit pieces, nuts, chocolate gratings, vanilla pods, coffee andcereals.

After removal from the coating solution, in accordance with the firstembodiment of the invention, the coated core, now with a layer of thecoating solution is again cooled to a temperature which falls in therange described for initial cooling of the core surface. Thereby thereis ensured a stronger adherence of the coating layer to the ice core anda hardening is effected. The crystal size in the coating layer is keptsmall by these means.

With the second embodiment of the present invention, this repeatedcooling step is not necessary. Thereby, however, it is important thatthe temperature of the coating layer, after removal from the coatingsolution, lies at approximately storage temperature, i.e. between about−18 to −28° C. As a result of the great temperature difference betweenthe ice core and the coating solution the cold capacity of the ice coreis so high that a rapid formation and immediate adherence of smallcrystals to the ice core is brought about. Since the coating layer,after removal from the coating solution, in accordance with theinvention should have at most storage temperature, a further crystalgrowth in the coating layer is avoided.

In accordance with the invention, the method steps according to both thefirst embodiment and also according to the second embodiment, can berepeated a plurality of times with different temperature parameters inorder to form a plurality of coating layers over one another or toincrease the desired layer thickness. It is also possible, by means ofseveral repeats of the method steps, to form layers of different coatingmaterials over one another. Finally, it is possible to so combine themethod steps according to the first and second embodiments that forexample initially one or more coating layers in accordance with themethod of the second embodiment are formed and then the final, uppermostcoating layer is formed with the method of the first embodiment with thesame coating solution as for the preceding layers or with differentcoating solutions.

The following examples explain the invention, without restricting theinvention. In the examples, exemplary compositions are indicated whichwere used as coating solutions.

EXAMPLE 1

A core of ice cream is extruded in known manner and a stick introducedin the core. The ice core is delivered into a hardening tunnel andbrought to a temperature of −22° C. Then, the thus pre-cooled ice creamproduct is dipped for 15 seconds in liquid nitrogen, whereby a surfacetemperature of below −40° C. is obtained. The ice cream is than dippedfor 7 seconds in a coating solution having the following composition.

Row materials Weight % Glucose syrup  5.00 Water 24.50 Cream 36% 50.00Skimmed milk concentrate 10.00 Sugar 10.00 Emulsifier  0.30 Carob flour 0.10 Flavouring: vanilla  0.10 TOTAL: 100.00 

The ice cream product was then removed from the coating solution andagain dipped in liquid nitrogen for 14 seconds. The product was thanpacked and stored in conventional manner.

The thus produced two-component ice cream product had a smooth andcreamy surface. As a result of the creamy consistency of the coatinglayer, surprisingly, the taste of the ice cream core came to betteradvantage.

EXAMPLE 2

The method of Example 1 was repeated, with the proviso that the dippingtime in the liquid nitrogen was 18 seconds. The dipping time in thecoating solution was 7 seconds. The following solution was used ascoating solution:

Vegetable fat-chocolate Row materials Weight % Glucose syrup 4.00 Water39.50  Coconut fat 15.00  Skinned milk concentrate 22.00  Sugar 12.00 Dextrose 3.00 Stabilizer carob flour 0.20 Emulsifier 0.30 Cacao 10/122.00 Cacao 20/22 2.00 TOTAL: 100.00 

The two-component ice cream product thus produced likewise had a smoothand creamy surface. It was also manifest here that due to the creamyconsistency of the coating layer the flavour of the ice cream core cameto better advantage.

EXAMPLE 3

The method of Example 1 was repeated, the conditions remaining asexplained in this example. The following solution was used as coatingsolution:

Yoghurt - ice cream Row materials Weight % Glucose syrup  4.00 Water19.40 Butter fat 15.00 Skimmed milk concentrate 11.00 Sugar 12.00Dextrose  3.00 Stabilizer carob flour  0.10 Emulsifier  0.30 Yoghurt35.00 Flavouring: Yoghurt  0.20 TOTAL: 100.00 

The two-component ice cream product produced with this coating solutionhad a smooth and creamy surface. Here also it was determined by tastingthat due to the creamy consistency of the coating layer the flavour ofthe ice cream core came to better advantage.

EXAMPLE 4

A two-component ice cream was produced on the basis of the secondembodiment in accordance with the invention. Thereby, the ice creamobtained as in Example 1 was dipped for 20 seconds each in a coatingsolution in accordance with Examples 1 to 3 (dipping time 5 seconds),the product so obtained then being transferred immediately into a zonehaving storage temperature.

The thus-obtained two-component ice cream products all had smooth andcreamy surfaces and the flavour of the ice cream core came to betteradvantage.

What is claimed is:
 1. Method for the production of a two-component icecream, in which the surface of a frozen core of ice cream is brought toa temperature of below at least about −15° C., the surface of the coreis dipped into a fat-containing coating solution for a period of timesufficient to form a quantity of the solution as an even layer on thecore, the coating solution having a fat content of at least about 10%and the obtained layer having an aeration between 0 and 30% referred tothe volume of the coating solution, whereafter the whole is again cooledto a surface temperature of below at least about −15° C. in order toharden the fat-containing layer on the frozen ice core of ice cream. 2.Method according to claim 1, in which the aeration is 0 to 10% of thevolume of the coating solution.
 3. Method according to claim 2, in whichno aeration is present in the coating.
 4. Method according to claim 1,in which the fat content of the coating solution is 15 to 18%.
 5. Methodaccording to claim 1, wherein the fat is milk fat or vegetable fat or amixture thereof.
 6. Method according to claim 5, in which the vegetablefat is coconut fat or cocoa fat or a mixture thereof.
 7. Methodaccording to claim 1, in which the core is dipped in a cryogenic liquid,for cooling.
 8. Method according to claim 7, in which the cryogenicliquid is nitrogen or carbon dioxide.
 9. Method according to claim 8, inwhich the ice core is dipped in liquid nitrogen for a time period of 7to 25 seconds.
 10. Method for the production of a two-component icecream, in which the surface of a frozen core of ice cream is brought toa temperature of below at least about −40° C., the surface of the coreis dipped into a fat-containing coating solution for a period of timesufficient to form a quantity of solution as an even layer on the core,the coating solution having a fat content of at least about 10% and theobtained layer having an aeration between 0 and 30% referred to thevolume of the coating solution, and the formation of the layer is soeffected that the coating layer of the thus obtained ice cream productafter the dipping has at least storage temperature or lower.
 11. Methodaccording to claim 10, in which the aeration is 0 to 10% of the volumeof the coating solution.
 12. Method according to claim 11, in which noaeration is present in the coating.
 13. Method according to claim 10, inwhich the coating solution has a temperature between 0 and 10° C. upondipping of the core.
 14. Method according to claim 10, wherein the fatis milk fat or vegetable fat or a mixture thereof.
 15. Method accordingto claim 14, in which the vegetable fat is coconut fat or cocoa fat or amixture thereof.
 16. Method according to claim 10, in which the core isdipped in a cryogenic liquid, for cooling.
 17. Method according to claim16, in which the cryogenic liquid is nitrogen or carbon dioxide. 18.Method according to claim 17, in which the ice core is dipped in liquidnitrogen for a time period of 7 to 25 seconds.